Modelagem e controle de uma incubadora neonatal

Abstract

This work presents an introduction about neonatology history, the concept and mathematical modeling of a neonatal incubator’s thermal system, with its thermal exchanges relations to an infant by the first law of thermodynamics. The method used for linearization (Taylor series) it is showed and the operation points calculated to the linear system obtained in the state space format, and then a representation in transfer function format. By the system’s mathematical modelling, an open loop test was done to verify the model behaviour, as characteristics of stability, time constant and convergence to a desired final value, and how the system operates at closed-loop, the system on this configuration was tested with the usage of an unitary gain. The behaviour of the non linear system was compared to the linearized system through their time response curves at a presence of a degree input to the verification of the linearized representation validity, and after the validation, bode diagrams were generated to different model parameters, to notice the effect of this variation on the model’s dynamic behaviour, and was observed that the model’s behaviour do not vary at a substantial form inside the verified ranges of values. A proportional and integral (PI) controller then was designed to eliminate the steady-state error present at the system’s time response. Tests under few operating conditions were done at the linear representation and the temperature variation curves were obtained with the controller applied to the non linear model, and the results were considered satisfactory to this kind of application. This work was made with the assistance of computational tool Simulink of the software Matlab®.